There is growing interest in the use of OFETs in device structures, where an active channel of the transistor is made from an organic semiconductive material. OFETs can be manufactured in fewer steps, using less expensive materials, than transistors based on silicon technologies. One desirable application for OFETs is dual transistor structures, such as an inverters. Inverters are fundamental to many electronic devices, including logic devices, ring oscillators, and other devices well known to skilled in the art.
A conventional inverter has one n-type transistor and one p-type transistor in a side-by-side arrangement. The fabrication of a conventional inverter made from OFETs therefore requires two separate processes to fabricate the n-type OFET and the p-type OFET. The use of two separate processing schemes for each type of OFET increases the expense and complexity to fabricate the inverter. In addition, a side-by-side arrangement of transistors occupies an undesirably large area, making device miniaturization difficult.
The present invention overcomes these problems by providing a simplified processing scheme to form a stacked pair of OFETs, resulting in a novel dual transistor structure.